CVE-2019-3878

Name: CVE-2019-3878
Creator: NVD / NIST
Published: 2019-03-26T18:29:00.983+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

UnknownEPSS 2.97%

Last modified Jun 17, 2026

CVE-2019-3878 is a vulnerability of currently unknown severity. A vulnerability was found in mod_auth_mellon before v0.14.2. If Apache is configured as a reverse proxy and mod_auth_mellon is configured to only let through authenticated users (with the require valid-user directive), adding special HTTP headers that are normally used to start the special SAML ECP (non-browser based) can be used to bypass authentication.. EPSS estimates a 2.97% chance of exploitation in the next 30 days.

Description

A vulnerability was found in mod_auth_mellon before v0.14.2. If Apache is configured as a reverse proxy and mod_auth_mellon is configured to only let through authenticated users (with the require valid-user directive), adding special HTTP headers that are normally used to start the special SAML ECP (non-browser based) can be used to bypass authentication.

Metrics

EPSS Probability

2.97%

85.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Mod Auth Mellon Project	Mod Auth Mellon	< 0.14.2
Fedoraproject	Fedora	29
Fedoraproject	Fedora	30
Redhat	Enterprise Linux	7.0
Redhat	Enterprise Linux Desktop	7.0
Redhat	Enterprise Linux Server	7.0
Redhat	Enterprise Linux Server Aus	7.6
Redhat	Enterprise Linux Server Eus	7.6
Redhat	Enterprise Linux Server Tus	7.6
Redhat	Enterprise Linux Workstation	7.0
Canonical	Ubuntu Linux	18.04
Canonical	Ubuntu Linux	18.10

References

https://access.redhat.com/errata/RHBA-2019:0959
https://access.redhat.com/errata/RHSA-2019:0746Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0766Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0985
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3878Issue Tracking, Patch, Third Party Advisory
https://github.com/Uninett/mod_auth_mellon/pull/196Exploit, Patch, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CNW5YMC5TLWVWNJEY6AIWNSNPRAMWPQJ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X7NLAU7KROWNTHAYSA2S67X347F42L2I/
https://usn.ubuntu.com/3924-1/Third Party Advisory
https://access.redhat.com/errata/RHBA-2019:0959
https://access.redhat.com/errata/RHSA-2019:0746Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0766Third Party Advisory
https://access.redhat.com/errata/RHSA-2019:0985
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3878Issue Tracking, Patch, Third Party Advisory
https://github.com/Uninett/mod_auth_mellon/pull/196Exploit, Patch, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CNW5YMC5TLWVWNJEY6AIWNSNPRAMWPQJ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/X7NLAU7KROWNTHAYSA2S67X347F42L2I/
https://usn.ubuntu.com/3924-1/Third Party Advisory

Timeline

Published: Mar 26, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-3878?

How severe is CVE-2019-3878?

Severity scoring for CVE-2019-3878 is pending analysis. The EPSS model estimates a 2.97% probability of exploitation in the next 30 days.

How do I fix CVE-2019-3878?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2019-3878?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST